orbitdb/README.md
2016-05-08 18:11:46 +02:00

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# OrbitDB
## Introduction
Distributed, peer-to-peer database on IPFS.
This is the Javascript implementation and it works both in **Node.js** and **Browsers**.
- Client-side database to be embedded in Javascript applications
- Stores all data in IPFS
- Aggregation happens on client side and data is eventually consistent
- Designed to work offline first
**NOTE: the README can be out of date, I'm working to get up to date. If you find a problem, please open an issue or a PR.**
_Currently requires [orbit-server](https://github.com/haadcode/orbit-server) for pubsub communication. This will change in the future as soon as IPFS provides pubsub._
![Screenshot](https://raw.githubusercontent.com/haadcode/orbit-db/master/screenshot.png)
## Install
```
npm install orbit-db
```
## Examples
### Node.js examples
*To run the examples, make sure to run a local [orbit-server](https://github.com/haadcode/orbit-server)*
Before running the examples, install dependencies with:
```
npm install
```
Key-Value store [example](https://github.com/haadcode/orbit-db/blob/master/examples/keyvalue.js):
```
node examples/keyvalue.js <host> <username> <channel> <key> <value>
```
Event log [example](https://github.com/haadcode/orbit-db/blob/master/examples/eventlog.js) (run several in separate shells):
```
node examples/eventlog.js <host> <username> <channel> <data> <interval in ms>
```
Benchmark writes:
```
node examples/benchmark.js <host> <username> <channel>;
```
### Browser examples
In order to run the browser example, you need to have a local IPFS daemon running. Start it with the following command:
```
API_ORIGIN=* ipfs daemon
```
Then open `examples/browser.html`. See the full example [here](https://github.com/haadcode/orbit-db/blob/master/examples/browser.html).
```html
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<script type="text/javascript" src="orbitdb.min.js" charset="utf-8"></script>
<script type="text/javascript" src="ipfsapi.min.js" charset="utf-8"></script>
<script type="text/javascript">
const ipfs = IpfsApi();
OrbitDB.connect('QmRB8x6aErtKTFHDNRiViixSKYwW1DbfcvJHaZy1hnRzLM', 'user1', '', ipfs).then((orbit) => {
orbit.kvstore('test').then((db) => {
db.put('hello', 'world').then((res) => {
const result = db.get(key);
console.log(result);
});
});
});
</script>
</body>
</html>
```
## API
**NOTE: the API documentation is currently out of date. It will be updated soon!**
_See usage example below_
_OrbitDB calls its namespaces channels. A channel is similar to "table", "keyspace", "topic", "feed" or "collection" in other db systems._
connect(host, port, username, password)
channel(name, password)
.add(data: String) // Insert an event to a channel, returns <ipfs-hash> of the event
.iterator([options]) // Returns an iterator of events
// options : {
// gt: <ipfs-hash>, // Return events newer than <ipfs-hash>
// gte: <ipfs-hash>, // Return events newer then <ipfs-hash> (inclusive)
// lt: <ipfs-hash>, // Return events older than <ipfs-hash>
// lte: <ipfs-hash>, // Return events older than <ipfs-hash> (inclusive)
// limit: -1, // Number of events to return, -1 returns all, default 1
// reverse: true // Return items oldest first, default latest first
// }
.put(key, data: String) // Insert (key,value) to a channel
.get(key) // Retrieve value
.del({ key: <key or hash> }) // Remove entry
.delete() // Deletes the channel, all data will be "removed" (unassociated with the channel, actual data is not deleted from ipfs)
## Usage
```javascript
const async = require('asyncawait/async');
const ipfsAPI = require('ipfs-api');
const OrbitDB = require('orbit-db');
// local ipfs daemon
const ipfs = ipfsAPI();
async(() => {
// Connect
const orbit = await(OrbitClient.connect('QmRB8x6aErtKTFHDNRiViixSKYwW1DbfcvJHaZy1hnRzLM', 'usernamne', '', ipfs));
/* Event Log */
const eventlog = orbit.eventlog('eventlog test');
const hash = await(eventlog.add('hello')); // <ipfs-hash>
// Remove event
await(eventlog.remove(hash));
// Iterator options
const options = { limit: -1 }; // fetch all messages
// Get events
const iter = eventlog.iterator(options); // Symbol.iterator
const next = iter.next(); // { value: <item>, done: false|true}
// OR:
// var all = iter.collect(); // returns all elements as an array
// OR:
// for(let i of iter)
// console.log(i.hash, i.item);
/* Delete database locally */
eventlog.delete();
/* KV Store */
const kvstore = orbit.kvstore('kv test');
await(kvstore.put('key1', 'hello world'));
kvstore.get('key1'); // returns "hello world"
await(kvstore.del('key1'));
})();
```
### Development
#### Source Code
The entry point for the code is [src/Client.js](https://github.com/haadcode/orbit-db/blob/master/src/Client.js) and the DB implementation is [src/OrbitDB.js](https://github.com/haadcode/orbit-db/blob/master/src/OrbitDB.js)
#### Run Tests
```
npm test
```
Keep tests running while development:
```
mocha -w
```
#### Lint
*Work in progress! Throws an error "Parsing error: The keyword 'await' is reserved".*
```
npm run lint
```
### TODO
- make ipfs-log emit events ('data', 'load')
- Store: this._log.events.on('data', (log, entries) => this._index.updateIndex(log, entries))
- merge 'readable' and 'data' events (only one)
## Notes
### Data structure description
*For future [IPLD](https://github.com/ipfs/ipld-examples) references*
List snapshots are posted to pubsub:
```
> QmRzWAiFdLkdkwBDehzxhHdhfwbDKDnzqBnX53va58PuQu
> ...
```
**Get a list snapshot**
`ipfs object get QmRzWAiFdLkdkwBDehzxhHdhfwbDKDnzqBnX53va58PuQu`
```json
{
"Links": [],
"Data": {
"id": "user123",
"items": [
"QmNwREbsgGgiQPXxpvGanD55inFjUXjpEqjiPtpa39P7Mn",
"QmQxndNEzWxKT5KRqRsty7JDGcbPVazaYPCqfB5z1mxmon",
"QmUN1X97M2t8MX55H8VoPGXu2fLBpr91iCAzHkXudSMvDE"
]
}
}
```
**Get the item**
`ipfs object get QmNwREbsgGgiQPXxpvGanD55inFjUXjpEqjiPtpa39P7Mn`
```json
{
"Links": [],
"Data": {
"id": "user123",
"data": "QmasZEUwc67yftPvdSxRLWenmvF8faLnS7TMphQpn4PCWZ",
"next": [
"QmS17ABxzFEVoHv5WEvATetNEZhN2vkNApRPcFQUaJfij3"
]
}
}
```
**Get the item's data (operation)**
`ipfs object get QmasZEUwc67yftPvdSxRLWenmvF8faLnS7TMphQpn4PCWZ`
```json
{
"Links": [],
"Data": {
"op": "PUT",
"key": "default",
"value": "QmaAPEKDdaucQZRseJmKmWwZhgftBSwj8TD1xEomgcxo1X",
"meta":{
"type": "text",
"size": -1,
"from": "user123",
"ts": 1456494484094
}
}
}
```
**Get the value**
`ipfs object get QmaAPEKDdaucQZRseJmKmWwZhgftBSwj8TD1xEomgcxo1X`
```json
{
"Links": [],
"Data": {
"content": "LambOfGod 347",
"ts": 1456494484089
}
}
```